The polymerization of various butenes, whether mixtures containing 1-butene, 2-butene and isobutene or only one or two of these isomers, using aluminum halide catalysts is known. Aluminum trichloride polymerization catalysts, often in conjunction with co-catalysts (or promoters) such as hydrogen chloride, alcohols or water, have been used to produce polybutenes. These catalysts typically are introduced into the reactor feed at a temperature, pressure and in such a fashion (e.g., as a suspended particle) that the catalysts stay highly dispersed until the polymerization reaction is considered to be complete Quite obviously, the polymeric product is more viscous than is the monomer feed. Consequently, termination of the polymerization reaction at a desired conversion or product molecular weight and removal of the dispersed catalyst from the viscous polymeric solution can be difficult.
Patents which are representative of these processes include U.S. Pat. Nos. 2,698,320 and 2,779,753. These show the polymerization of isobutylene using solid particulate aluminum trichloride.
U.S. Pat. Nos. 2,856,392 and 2,856,393 discusses the problem of equipment plugging which occurs when using aluminum trichloride particles as an isobutylene polymerization catalyst. The patent suggests drying the monomer diluents prior to introducing the monomer into the reaction zone. The drying medium is desirably granular aluminum chloride, alumina and/or bauxite
Other disclosures include U.S. Pat. No. 2,957,930, which shows the use of 10 to 20% AlCl.sub.3 catalyst in the production of polyisobutylene from a C.sub.1 -C.sub.5 petroleum gas feedstock with 0 08 to 0.12 percent HCl, relative to AlC13, used as a catalyst promoter. This reference notes that correspondingly small quantities of water vapor chloroform, which can react with AlCl.sub.3 to release HCl, may also be used. British Patent 1,195,760 (1970) discloses the production of olefin polymer by polymerization in the presence of the catalyst comprising a liquid complex of AlCl.sub.3, HCl and an alkyl benzene. Polymerization products of materials other than polyisobutylene and products having a narrow molecular weight distribution are disclosed in this reference.
U.S. Pat. No. 3,119,884 discloses a series of vertical column reactors useful for polymerizing isobutylene. It further discloses a catalyst system of AlCl.sub.3 and HCl (or a substance which generates HCl). The catalyst system is described as an acid promoted AlCl.sub.3 catalyst. In such a system, a reaction between HCl and AlCl.sub.3 occurs to form H.sup.+ AlCl.sub.4 .sup.-. This species initiates polymerization. According to this patent, one method of introducing the catalysts and reactant to the reactor is to introduce the three materials, i.e., AlCl.sub.3, HCl and liquid feed, through the same duct. This should result in the exothermic polymerization reaction beginning in the duct line where the temperature is not controlled by the refrigeration system of the reactor. Any product formed under these conditions should have an undesirably low molecular weight and broad molecular weight distribution.
U.S. Pat. Nos. 3,200,169 and 3,200,170 deal with the separation methods practiced after polymerization of propylene or butylene feeds. The process utilizes an ammonia treatment process. HCl is disclosed as a catalyst promoter which may be added to the reaction zone along with an AlCl.sub.3 catalyst.
U.S. Pat. No. 3,985,822 relates to the production of poly-n-butenes by use of AlCl.sub.3 promoted with HCl, but the objective is to reduce the isobutylene content of the polymer product.
U.S. Pat. No. 3,997,129 discloses synthesis of polybutenes from a C.sub.1 -C.sub.5 liquefied refinery stream in which the catalyst is a solid, particulate AlC13 promoted with HCl gas or its equivalent. This process employs a static mixer for mixing catalysts and feed prior to conducting polymerization.
Two other references suggest the reaction of gaseous olefin over solid aluminum/chlorine-containing catalysts. They are U.S. Pat. Nos. 2,040,658 and 2,329,714.
U.S. Pat. No. 2,329,714 relates to a process for forming lubricating oils by the polymerization of gaseous olefins (principally propylene, alpha-butylene and the amylenes) by introducing the gaseous olefin into a bed of solid catalyst (e.g., aluminum chloride) while a solvent (benzene) is led over the catalyst in a continuous stream. The patentee discloses that the solid catalyst may generally be employed in fairly large quantities to achieve usefully high throughputs and for this reason it is generally not advantageous to use it on carriers. The aluminum chloride loses its solid form as a result of the formation of syrupy addition products, which are likely complexes formed in the reactor between the catalyst, the benzene and HCl generated by trace water in the feed. Therefore, the patentee employs the aluminum chloride as a finely powdered solid distributed in layers of porous materials (e.g., diatomite or pumice) which are capable of retaining the syrupy substances.
U.K. Patent Application 2,001,662 relates to a method for producing polybutenes by passing the liquid monomer feed through a fixed bed of catalyst material comprising a Lewis Acid chloride (e.g., AlCl.sub.3) catalyst intercalated within graphite. The catalyst is prevented from being fluidized during passage of the feed therethrough by packing the catalyst between layers of packing material which fill the remaining portions of the reactor. The feed moisture level is reduced to less than 20 ppm water, and HCl is optionally added to the gas feed as a co-catalyst. The patentees indicate that it is generally accepted that fixed bed catalyst systems, in conjunction with butene feeds, will yield only dimers and trimers of the butene, and that the prior art had not developed any fixed bed method wherein polymerization of butenes could be achieved with a catalyst having an extended life span and which does not contaminate the final product.
U.S. Pat. No. 4,288,649 relates to the production of polyisobutylene wherein isobutylene is polymerized in a liquid phase using a halided alumina catalyst, which can be prepared by contacting an activated alumina at temperatures above about 100.degree. C. with such Cl-containing compounds as CCl.sub.4 and chloroform. The halided alumina catalyst can be employed in a tubular reactor.
U.S. Pat. No. 4,400,493 relates to the polymerization of isobutylene in which the exothermic heat of reaction is removed by vaporizing unreacted hydrocarbons to maintain a constant controlled reaction temperature and pressure. Finely divided particles of aluminum trichloride are illustrated in a catalyst slurry. The patentee also suggests that the polymerization process can also be employed in a fixed catalyst bed, although no detailed teachings are contained thereto. The patent indicates that recycle rate within the reactor of about 10 times the fresh feed rate is important to the illustrated process.
U.S. Pat. No. 4,463,212 relates to oligomerization of of olefins employing a catalyst comprising a metal halide intercalated in a carbon matrix at 50 to 350.C. The process is illustrated with, inter alia, a catalyst comprising aluminum chloride intercalated in graphite at 200.degree. C. for the oligomerization of propylene; a mixture of propylene dimers were obtained.
U.S. Pat. No. 3,109,041 relates to the polymerization of isobutylene in a 2-stage process. In the first stage, a Friedel-Crafts catalyst (e.g., aluminum trichloride) which is soluble in either the diluent, reactants or reaction products, is employed. The patentee indicates that the reaction vessel can comprise a tank having mechanical mixing means or a tubular reactor. The effluent from the first reaction stage, including catalyst, is then passed through a fixed bed reactor to polymerize the balance of the unreacted isobutylene. The fixed bed reactor comprises a Friedel-Crafts halide on an adsorbent supporting material, which can comprise activated carbon, silica, alumina and mixtures thereof. The effluent from the second stage reaction is said to comprise essentially polyisobutylene, hydrocarbon solvent and minor amounts of catalyst entrained or dissolved in the reaction product. This second stage effluent is then passed over an adsorbent bed, comprised of activated carbon, silica, alumina or mixtures thereof. The patentee discloses that the second stage reactor having the supported catalyst becomes ineffective over extended use due to buildup of polymer and the formation of non-active catalyst complexes. At the same time, the absorbent in the absorber unit is said to absorb the entrained catalyst, which then builds up and converts the absorber unit into a unit exhibiting substantial catalytic activity for polymerizing isobutylene monomer. The process was illustrated by the patentee employing titanium tetrachloride and boron trifluoride to product polyisobutylenes having average molecular weight of 680 and 636, respectively. In each illustration, the second stage fixed bed catalyst comprised titanium tetrachloride or boron trifluoride on silica gel.
U.S. Pat. No. 3,558,737 relates to a process for polymerization of propylene and butenes by contacting the olefin with a catalyst composed of a gamma alumina and chlorine or bromine having a surface area of 75 to 150 square meters per gram and containing about 3 to 15 weight percent chlorine and bromine.
U.S. Pat. No. 3,497,568 relates to a process of polymerizing olefins of 3 to 5 carbon atoms wherein the liquefied mixture of an olefin feedstream is passed upwardly through a vertical elongated reaction vessel partially loaded with silica gel in the lower portion of the reactor while introducing a catalyst solution of aluminum bromide and hydrogen bromide into the reactor at a point adjacent to the upper level of the bed of silica gel. An effluent containing the polymerization reaction products is recovered from the top of the reactor. The catalyst for this reaction is aluminum bromide promoted with hydrogen bromide.
Y. A. Sangalov, et al., Vvsokomol. Soedin. Ser. B 25 #5, 317-320 (1983) prepared immobilized cationic catalysts for polymerization of isobutylene by reaction of Gustavson complexes of the general formula a ArHXMeX.sub.n (Ar =aromatic hydrocarbon, HX Bronstedt acid, MeXn =Lewis Acid, a=3-6) with polystyrene or cross-linked divinylbenzene-styrene copolymer.
None of these references suggest the production of polybutenes using liquid butenes and a fixed bed of a granular aluminum chloride catalyst